8.2 summary

Chloroplasts are like chemical factories inside plant cells. To run these factories energy comes from the sun. Sunlight is a form of electromagnetic energy that can travel in waves, the adjzcent difference between two waves are called waveengths. Wavelengths are measured through the Electromagnetic Spectrum. A substance's colour is determined by its pigments where it absorbs, transmits, or reflects light waves, this can be discovered through Paper Chromatography. Within the thylakoid membrane, chlorophyll and other molecules are arranged in clusters. Light reactions change light energy into chemical energy through two processes; water-splitting photosystem and the NADPH-producing photosystem.

Wavelength-the distance between two adjacent waves
Electromagnetic Spectrum-the range of electromagnetic energy from gamma to radio waves
Pigment-chemical compounds that give color to a substance
Paper Chromatography-a laboratory technique that is used to observe the pigments inside a leaf
Photosystem-cluster of chlorophyll and other molecules inside a thylakoid

Concept Check
1. A leaf looks green because it absorbs all the different types of rays except green.
2.When a chlorophyll molecule absorbs light they turn an electron excited from ground state to excited state, it causes the electron to jump from molecule to molecule until it gets turned into ATP or NADPH through the primary electron acceptor.
3.Besides oxygen, light reactions also produce ATP and NADPH molecules.
4.Light reactions take place inside the thylakoid, inside the chloroplast.

8.1 summary

Photosynthesis is the process by which plants and other producers convert the energy of the sunlight into the energy stored in organic molecules. Cellular respiration occurs in a chloroplast that contains an inner membrane filled with Thylakoids within a thick fluid called Stroma. The two main stages of Photosynthesis are the light reactions followed by the calvin cycle. The light reaction converts sunlight to chemical energy, its chlorophylls capture sunlight and the chloroplasts separate electrons from water molecules, electrons and hydrogen ions make NADPH, which generate ATP from sunlight. The Calvin cycle produces sugars from the atoms in carbon dioxide including hydrogen ions and high energy electrons.

Chloroplast-A structure in cells where photosynthesis takes place
Chlorophyll-chemical compounds in Chloroplasts that give organelles its green colour
Stroma-Thick fluid that encloses the inner membrane Thylakoid-Disk shaped sacs suspended in the stroma in the inner membrane Light reactions-Conversion of sunlight into chemical energy
Calvin Cycle-creation of sugar from the atoms in carbon dioxide including hydrogen ions and high energy electrons.

Concept Check
1. Image from: http://kybiologywonderland.blogspot.com/

2. The reactants for photosynthesis are CO2 and H2O and the products are glucose and O2.

3.The two main stages of photosynthesis are Light reactions and Calvin Cycle, the light reactions supply the Calvin Cycle with energy then Calvin Cycle supplies them back with carriers that collect ATP energy and electrons.